Effects of interleukin-17A on liver and kidney injury and prognosis in septic mice / 中华危重病急救医学

OBJECTIVE@#To explore the effect of interleukin-17A (IL-17A) on liver and kidney injury and prognosis in septic mice.@*METHODS@#A total of 84 SPF male C57BL/6 mice were randomly divided into sham operation group (Sham group), cecal ligation and puncture (CLP) induced sepsis model group (CLP group), and IL-17A intervention group. IL-17A intervention group were then divided into five subgroups according to the dose of IL-17A (0.25, 0.5, 1, 2, 4 μg). Mice in the IL-17A intervention group were intraperitoneally injected with the corresponding dose of IL-17A 100 μL immediately after surgery. The other groups were intraperitoneally injected with 100 μL phosphate buffer solution (PBS). The survival rate of mice was observed at 7 days, and peripheral blood and liver, kidney and spleen tissues were collected. According to the 7-day survival, another 18 mice were randomly divided into Sham group, CLP group, and 1 μg IL-17A intervention group. Peripheral blood samples were collected at 12 hours and 24 hours after CLP, and the mice were sacrificed to obtain liver, kidney, and spleen tissues. The behavior and abdominal cavity of each group were observed. The levels of peripheral blood liver and kidney function indexes and inflammatory factors were detected. The histopathological changes of liver and kidney were observed under light microscope. The peripheral blood and spleen tissues were inoculated in the medium, the number of bacterial colonies was calculated, and the bacterial migration of each group was evaluated in vitro.@*RESULTS@#Except for the Sham group, the 7-day survival rate of mice in the 1 μg IL-17A intervention group was the highest (75.0%), so this condition was selected as the intervention condition for the subsequent study. Compared with Sham group, the liver and kidney functions of CLP group were significantly damaged at each time point after operation. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (SCr) reached the peak at 24 hours after operation, and the liver and kidney pathological scores reached the peak at 7 days after operation, the levels of inflammatory cytokines interleukin (IL-17A, IL-6, IL-10) reached the peak at 12 hours after operation, and tumor necrosis factor-α (TNF-α) reached the peak at 24 hours after operation. In addition, a large number of bacteria proliferated in the peripheral blood and spleen, which reached the peak on day 7. Compared with the CLP group, exogenous administration of 1 μg IL-17A significantly delayed the rising trend of each index in the early stage of sepsis [24-hour ALT (U/L): 166.95±5.20 vs. 271.30±6.11, 24-hour AST (U/L): 599.42±7.25 vs. 1 013.27±3.37, 24-hour BUN (mg/L): 815.4±26.3 vs. 1 191.2±39.4, 24-hour SCr (μmol/L): 29.34±0.87 vs. 60.75±3.83, 7-day liver pathological score: 2.50 (2.00, 3.00) vs. 9.00 (8.50, 9.00), 7-day kidney pathological score: 1.00 (1.00, 2.00) vs. 5.00 (4.50, 5.00), 12-hour IL-17A (ng/L): 105.21±0.31 vs. 111.28±1.37, 12-hour IL-6 (ng/L): 83.22±1.01 vs. 108.88±0.99, 12-hour IL-10 (ng/L): 731.54±3.04 vs. 790.25±2.54, 24-hour TNF-α (μg/L): 454.67±0.66 vs. 576.18±0.76, 7-day peripheral blood colony count (CFU/mL): 600 (400, 600) vs. 4 200 (4 200, 4 300), 7-day spleen tissue colony count (CFU/g): 4 600 (4 400, 4 600) vs. 23 400 (23 200, 23 500), all P < 0.05].@*CONCLUSIONS@#Appropriate dose (1 μg) of exogenous IL-17A can reduce the lethal inflammatory response induced by CLP and improve the ability of bacterial clearance, thereby alleviating liver and kidney injury and improving the 7-day survival rate of septic mice.

Effect and mechanism of Bovis Calculus on ulcerative colitis by inhibiting IL-17/IL-17RA/Act1 signaling pathway / 中国中药杂志

This study aimed to elucidate the effect and underlying mechanism of Bovis Calculus in the treatment of ulcerative colitis(UC) through network pharmacological prediction and animal experimental verification. Databases such as BATMAN-TCM were used to mine the potential targets of Bovis Calculus against UC, and the pathway enrichment analysis was conducted. Seventy healthy C57BL/6J mice were randomly divided into a blank group, a model group, a solvent model(2% polysorbate 80) group, a salazosulfapyridine(SASP, 0.40 g·kg~(-1)) group, and high-, medium-, and low-dose Bovis Calculus Sativus(BCS, 0.20, 0.10, and 0.05 g·kg~(-1)) groups according to the body weight. The UC model was established in mice by drinking 3% dextran sulfate sodium(DSS) solution for 7 days. The mice in the groups with drug intervention received corresponding drugs for 3 days before modeling by gavage, and continued to take drugs for 7 days while modeling(continuous administration for 10 days). During the experiment, the body weight of mice was observed, and the disease activity index(DAI) score was recorded. After 7 days of modeling, the colon length was mea-sured, and the pathological changes in colon tissues were observed by hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), and interleukin-17(IL-17) in colon tissues of mice were detected by enzyme-linked immunosorbent assay(ELISA). The mRNA expression of IL-17, IL-17RA, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1β, CXCL1, CXCL2, and CXCL10 was evaluated by real-time polymerase chain reaction(RT-PCR). The protein expression of IL-17, IL-17RA, Act1, p-p38 MAPK, and p-ERK1/2 was investigated by Western blot. The results of network pharmacological prediction showed that Bovis Calculus might play a therapeutic role through the IL-17 signaling pathway and the TNF signaling pathway. As revealed by the results of animal experiments, on the 10th day of drug administration, compared with the solvent model group, all the BCS groups showed significantly increased body weight, decreased DAI score, increased colon length, improved pathological damage of colon mucosa, and significantly inhibited expression of TNF-α,IL-6,IL-1β, and IL-17 in colon tissues. The high-dose BCS(0.20 g·kg~(-1)) could significantly reduce the mRNA expression levels of IL-17, Act1, TRAF2, TRAF5, TNF-α, IL-6, IL-1β, CXCL1, and CXCL2 in colon tissues of UC model mice, tend to down-regulate mRNA expression levels of IL-17RA and CXCL10, significantly inhibit the protein expression of IL-17RA,Act1,and p-ERK1/2, and tend to decrease the protein expression of IL-17 and p-p38 MAPK. This study, for the first time from the whole-organ-tissue-molecular level, reveals that BCS may reduce the expression of pro-inflammatory cytokines and chemokines by inhibiting the IL-17/IL-17RA/Act1 signaling pathway, thereby improving the inflammatory injury of colon tissues in DSS-induced UC mice and exerting the effect of clearing heat and removing toxins.

IL-17A/lL-17RA reduces cisplatin sensitivity of ovarian cancer SKOV3 cells by regulating autophagy / 南方医科大学学报

OBJECTIVE@#To investigate the effect of interleukin-17A (IL-17A) on chemosensitivity of ovarian cancer cells to cisplatin (DDP) and explore the mechanism in light of autophagy regulation.@*METHODS@#Ovarian cancer SKOV3 cells cultured @*RESULTS@#DDP increased the expression of IL-17RA in ovarian cancer SKOV3 cells. Treatment with IL-17A significantly reduced the susceptibility of SKOV3 cells to cisplatin-induced apoptosis (@*CONCLUSIONS@#IL-17A/IL-17RA can decrease chemosensitivity of SKOV3 cells to DDP by upregulating DDP-induced autophagy.

IL-17A activates mouse lung fibroblasts through promoting chemokine CXCL12 secretion / 浙江大学学报·医学版

OBJECTIVE@#To investigate the role of IL-17A in promoting the activation of lung fibroblasts and the secretion of chemokine CXCL12, and to explore the possible mechanism.@*METHODS@#Lung tissues of BALB/c mice were collected after intraperitoneal injection of recombinant mouse IL-17A (rmIL-17A). Real-time RT-PCR and Western blotting were used to detect the expression levels of α-smooth muscle actin (α-SMA) and collagen I in lung tissues, and immunohistochemical staining and real-time RT-PCR were used to determine the expression of CXCL12. Normal mouse primary lung fibroblasts were isolated and cultured, and identified by immunofluorescence staining with optical microscopy. Cells and supernatant of culture medium were collected after stimulation with rmIL-17A at different concentrations. mRNA levels of α-SMA, collagen I, and CXCL12 in the cells were determined by real-time RT-PCR, and the levels of collagen I and CXCL12 in the supernatant of culture medium were determined by ELISA.@*RESULTS@#The mRNA and protein levels of α-SMA and collagen I in the lung tissue of mice injected with rmIL-17A were significantly increased compared with the control group (all @*CONCLUSIONS@#s: IL-17A can promote the activation of lung fibroblasts and translation into myofibroblast. The secretion of collagen is increased, which promote the deposition of extracullular matrix, and leads to the occurrence and development of lung fibrosis. CXCL12, a chemokine secreted by activated fibroblasts, may be involved in this process.

Myeloid differentiation primary response protein 88 blockade upregulates indoleamine 2,3-dioxygenase expression in rheumatoid synovial fibroblasts

Indoleamine 2,3-dioxygenase (IDO) is a key negative regulator of immune responses and has been implicated in tumor tolerance, autoimmune disease and asthma. IDO was detected in the joint synovial tissue in the inflammatory microenvironment of rheumatoid arthritis (RA), but IDO expression in joint synovial tissue is not sufficient to overcome the inflamed synovial environment. This study aimed to unravel the mechanisms involving the failure to activate tolerogenic IDO in the inflamed joint. We demonstrate that both poly (I:C) and lipopolysaccharide (LPS) induce expression of IDO in synovial fibroblasts. However, inflammatory cytokines such as IL-17, TNF-alpha, IL-12, IL-23 and IL-16 did not induce IDO expression. Poly (I:C) appeared to induce higher IDO expression than did LPS. Surprisingly, toll-like receptor (TLR)4-mediated IDO expression was upregulated after depletion of myeloid differentiation primary response protein 88 (MyD88) in synovial fibroblasts using small interfering RNA (siRNA). IDO, TLR3 and TLR4 were highly expressed in synovial tissue of RA patients compared with that of osteoarthritis patients. In addition, RA patients with severe disease activity had higher levels of expression of IDO, TLR3 and TLR4 in the synovium than patients with mild disease activity. These data suggest that upregulation of IDO expression in synovial fibroblasts involves TLR3 and TLR4 activation by microbial constituents. We showed that the mechanisms responsible for IDO regulation primarily involve MyD88 signaling in synovial fibroblasts, as demonstrated by siRNA-mediated knockdown of MyD88.